Klatskin tumor

Klatskin tumor is a term that was traditionally given to a hilar cholangiocarcinoma, occurring at the bifurcation of the common hepatic duct. Typically, these tumors are small, poorly differentiated, exhibit aggressive biologic behavior, and tend to obstruct the intrahepatic bile ducts.

Epidemiology

They are thought to account for up to 25% of all cholangiocarcinomas ¹.

Radiographic features

For general imaging features of a cholangiocarcinoma refer to the main article.

Ultrasound

The presence of a hilar mass with obstruction would raise concern on ultrasound. The reported echotexture according to one study was ⁵:

• increased echogenicity relative to surrounding liver ~80%
• reduced echogenicity ~20%
• mixed echogenicity ~2%

Ultrasound may also show an intraluminal mass extending into the bile duct and in a small proportion of cases (4%), there may also be evidence of bile duct wall thickening.

CT/MRI

CT demonstrates the intrahepatic biliary radicle dilatation. The tumor mass itself is ill-defined and usually invisible however hilar necrotic lymph nodes or hepatic metastatic deposits could be identified. MRCP with its 3D capability is superior to CT to delineate the degree and location of the biliary tree stricture.

MRCP

The gold standard method for diagnosis of hilar cholangiocarcinoma. Shouldering and abrupt tapering at the stricture site suggest the diagnosis. Identifying the exact location and involvement can help in preoperative classification.

Staging

Determine the exact location of the tumor mass and can be used in the preoperative assessment. The Bismuth-Corlette system is one classification:

• type I: the lesion is limited to the common hepatic duct distal to the confluence of right and left ducts
• type II: the tumor involves the confluence of right and left hepatic ducts
• type III: the tumor involves one of the hepatic ducts
• type IV: the tumor invades the right and left hepatic ducts and hence it becomes unresectable

For more discussion on staging see "cholangiocarcinoma staging".

History and etymology

It is named after Gerald Klatskin (1910-86), American pathologist, New York.

Differential diagnosis

Imaging differential considerations include:

• biliary inflammatory pseudotumour: can be indistinguishable on imaging ⁶
• hepatic tuberculosis ⁸
• autoimmune cholangitis ⁹
• benign fibrosing disease at the hepatic confluence ¹⁰
• hepatocellular carcinoma ¹¹
• gallbladder carcinoma (invading the bile duct) ¹²

See also

• cholangiocarcinoma
• cholangiocarcinoma staging